1. Field of the Invention
The subject invention relates to a color wheel module for use in an optical engine and the optical engine comprising the color wheel module. More specifically, the subject invention relates to a module design for stabilizing the color wheel module in the optical engine.
2. Descriptions of the Related Art
Digital light processing (DLP) technology has been adopted in digital projection devices to generate digital images. The technology has been developed mainly by utilizing micro electro mechanical systems (MEMS), such as digital micromirror devices (DMD), as a basis for cooperation with other peripheral optical devices. FIG. 1 illustrates the main components of a prior DLP projection device 100. The DLP projection device 100 comprises a light source 102, a color wheel 104, a light tunnel 106, a lens assembly 108, a DMD 110, a projection lens 112, and so forth. In relation to the proceeding light direction, the projection device 100 can be divided into two major sub-systems: the illumination system, which includes the light source 102, the color wheel 104, the light tunnel 106, and the lens assembly 108; and the image system, which includes the DMD 110 and the projection lens 112.
The light projected from the light source 102 is separated into red, blue, and green colors via the color wheel 104, and then, sent into the light tunnel 106 for color combination. After light separation and combination via the lens assembly 108, the light enters into the DMD 110 and the image input signals are received by the DMD 110 so that the micromirrors (not shown) thereon will rotate to project the correct light and images onto the lens 112. Finally, the images can be displayed on a screen (not shown) via the lens 112. Compared with other optical engines, the DLP projection has high brightness quality, contrast, and lightness.
In the prior DLP projection devices, the components other than the light source 102 and the lens 112 are usually integrated into an optical engine (not shown) to meet the module requirement of the whole mechanism. Moreover, the color wheel 104 usually combines with a fixing base (not shown) to form a color wheel module. Accordingly, the color wheel can separate the light on the light path in the optical engine by fastening the fixing base on the frame. The fixing base is fastened to one end of the fixing base on the main body of the frame with at least one fixing mechanism, while the color wheel 104 rotates with a high speed actuated by a motor with a revolution speed per minute (RPM) ranging from several thousand RPMs to tens of thousands RPMs. With a high RPM, the single-direction fastening mechanism adopted by the prior color wheel will result in noises and vibrations in the DLP projection device.
Thus, in order to effectively suppress the noise and the vibration of the DLP projection device when the color wheel operates with the same structure and under certain costs, it is essential to improve the above-mentioned structure of the color wheel module so that the DLP projection device can keep silent and stable after a long term operation of the color wheel.